Commit 280df6b3 authored by Jamie Iles's avatar Jamie Iles Committed by Grant Likely
Browse files

basic_mmio_gpio: split into a gpio library and platform device

Allow GPIO_BASIC_MMIO_CORE to be used to provide an accessor library
for implementing GPIO drivers whilst abstracting the register access
detail.  Based on a patch from Anton Vorontsov[1] and adapted to allow
bgpio_chip to be embedded in another structure.

Changes since v1:
	- Register the gpio_chip in the platform device probe

1. https://lkml.org/lkml/2011/4/19/401



Signed-off-by: default avatarAnton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: default avatarJamie Iles <jamie@jamieiles.com>
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent e849dc04
......@@ -70,8 +70,14 @@ config GPIO_MAX730X
comment "Memory mapped GPIO drivers:"
config GPIO_BASIC_MMIO_CORE
tristate
help
Provides core functionality for basic memory-mapped GPIO controllers.
config GPIO_BASIC_MMIO
tristate "Basic memory-mapped GPIO controllers support"
select GPIO_BASIC_MMIO_CORE
help
Say yes here to support basic memory-mapped GPIO controllers.
......
......@@ -6,6 +6,7 @@ obj-$(CONFIG_GPIOLIB) += gpiolib.o
obj-$(CONFIG_GPIO_ADP5520) += adp5520-gpio.o
obj-$(CONFIG_GPIO_ADP5588) += adp5588-gpio.o
obj-$(CONFIG_GPIO_BASIC_MMIO_CORE) += basic_mmio_gpio.o
obj-$(CONFIG_GPIO_BASIC_MMIO) += basic_mmio_gpio.o
obj-$(CONFIG_GPIO_LANGWELL) += langwell_gpio.o
obj-$(CONFIG_GPIO_MAX730X) += max730x.o
......
......@@ -45,6 +45,7 @@ o ` ~~~~\___/~~~~ ` controller in FPGA is ,.`
*/
#include <linux/init.h>
#include <linux/err.h>
#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/module.h>
......@@ -61,44 +62,6 @@ o ` ~~~~\___/~~~~ ` controller in FPGA is ,.`
#include <linux/mod_devicetable.h>
#include <linux/basic_mmio_gpio.h>
struct bgpio_chip {
struct gpio_chip gc;
unsigned long (*read_reg)(void __iomem *reg);
void (*write_reg)(void __iomem *reg, unsigned long data);
void __iomem *reg_dat;
void __iomem *reg_set;
void __iomem *reg_clr;
void __iomem *reg_dir;
/* Number of bits (GPIOs): <register width> * 8. */
int bits;
/*
* Some GPIO controllers work with the big-endian bits notation,
* e.g. in a 8-bits register, GPIO7 is the least significant bit.
*/
unsigned long (*pin2mask)(struct bgpio_chip *bgc, unsigned int pin);
/*
* Used to lock bgpio_chip->data. Also, this is needed to keep
* shadowed and real data registers writes together.
*/
spinlock_t lock;
/* Shadowed data register to clear/set bits safely. */
unsigned long data;
/* Shadowed direction registers to clear/set direction safely. */
unsigned long dir;
};
static struct bgpio_chip *to_bgpio_chip(struct gpio_chip *gc)
{
return container_of(gc, struct bgpio_chip, gc);
}
static void bgpio_write8(void __iomem *reg, unsigned long data)
{
writeb(data, reg);
......@@ -284,20 +247,10 @@ static int bgpio_dir_out_inv(struct gpio_chip *gc, unsigned int gpio, int val)
return 0;
}
static void __iomem *bgpio_request_and_map(struct device *dev,
struct resource *res)
{
if (!devm_request_mem_region(dev, res->start, resource_size(res),
res->name ?: "mmio_gpio"))
return NULL;
return devm_ioremap(dev, res->start, resource_size(res));
}
static int bgpio_setup_accessors(struct platform_device *pdev,
struct bgpio_chip *bgc)
static int bgpio_setup_accessors(struct device *dev,
struct bgpio_chip *bgc,
bool be)
{
const struct platform_device_id *platid = platform_get_device_id(pdev);
switch (bgc->bits) {
case 8:
......@@ -319,13 +272,11 @@ static int bgpio_setup_accessors(struct platform_device *pdev,
break;
#endif /* BITS_PER_LONG >= 64 */
default:
dev_err(&pdev->dev, "unsupported data width %u bits\n",
bgc->bits);
dev_err(dev, "unsupported data width %u bits\n", bgc->bits);
return -EINVAL;
}
bgc->pin2mask = strcmp(platid->name, "basic-mmio-gpio-be") ?
bgpio_pin2mask : bgpio_pin2mask_be;
bgc->pin2mask = be ? bgpio_pin2mask_be : bgpio_pin2mask;
return 0;
}
......@@ -352,51 +303,22 @@ static int bgpio_setup_accessors(struct platform_device *pdev,
* - an input direction register (named "dirin") where a 1 bit indicates
* the GPIO is an input.
*/
static int bgpio_setup_io(struct platform_device *pdev,
struct bgpio_chip *bgc)
static int bgpio_setup_io(struct bgpio_chip *bgc,
void __iomem *dat,
void __iomem *set,
void __iomem *clr)
{
struct resource *res_set;
struct resource *res_clr;
struct resource *res_dat;
resource_size_t dat_sz;
res_dat = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dat");
if (!res_dat)
return -EINVAL;
dat_sz = resource_size(res_dat);
if (!is_power_of_2(dat_sz))
return -EINVAL;
bgc->bits = dat_sz * 8;
if (bgc->bits > BITS_PER_LONG)
return -EINVAL;
bgc->reg_dat = bgpio_request_and_map(&pdev->dev, res_dat);
bgc->reg_dat = dat;
if (!bgc->reg_dat)
return -ENOMEM;
res_set = platform_get_resource_byname(pdev, IORESOURCE_MEM, "set");
res_clr = platform_get_resource_byname(pdev, IORESOURCE_MEM, "clr");
if (res_set && res_clr) {
if (resource_size(res_set) != resource_size(res_clr) ||
resource_size(res_set) != resource_size(res_dat))
return -EINVAL;
bgc->reg_set = bgpio_request_and_map(&pdev->dev, res_set);
bgc->reg_clr = bgpio_request_and_map(&pdev->dev, res_clr);
if (!bgc->reg_set || !bgc->reg_clr)
return -ENOMEM;
return -EINVAL;
if (set && clr) {
bgc->reg_set = set;
bgc->reg_clr = clr;
bgc->gc.set = bgpio_set_with_clear;
} else if (res_set && !res_clr) {
if (resource_size(res_set) != resource_size(res_dat))
return -EINVAL;
bgc->reg_set = bgpio_request_and_map(&pdev->dev, res_set);
if (!bgc->reg_set)
return -ENOMEM;
} else if (set && !clr) {
bgc->reg_set = set;
bgc->gc.set = bgpio_set_set;
} else {
bgc->gc.set = bgpio_set;
......@@ -407,27 +329,18 @@ static int bgpio_setup_io(struct platform_device *pdev,
return 0;
}
static int bgpio_setup_direction(struct platform_device *pdev,
struct bgpio_chip *bgc)
static int bgpio_setup_direction(struct bgpio_chip *bgc,
void __iomem *dirout,
void __iomem *dirin)
{
struct resource *res_dirout;
struct resource *res_dirin;
res_dirout = platform_get_resource_byname(pdev, IORESOURCE_MEM,
"dirout");
res_dirin = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dirin");
if (res_dirout && res_dirin) {
if (dirout && dirin) {
return -EINVAL;
} else if (res_dirout) {
bgc->reg_dir = bgpio_request_and_map(&pdev->dev, res_dirout);
if (!bgc->reg_dir)
return -ENOMEM;
} else if (dirout) {
bgc->reg_dir = dirout;
bgc->gc.direction_output = bgpio_dir_out;
bgc->gc.direction_input = bgpio_dir_in;
} else if (res_dirin) {
bgc->reg_dir = bgpio_request_and_map(&pdev->dev, res_dirin);
if (!bgc->reg_dir)
return -ENOMEM;
} else if (dirin) {
bgc->reg_dir = dirin;
bgc->gc.direction_output = bgpio_dir_out_inv;
bgc->gc.direction_input = bgpio_dir_in_inv;
} else {
......@@ -438,60 +351,166 @@ static int bgpio_setup_direction(struct platform_device *pdev,
return 0;
}
static int __devinit bgpio_probe(struct platform_device *pdev)
int __devexit bgpio_remove(struct bgpio_chip *bgc)
{
int err = gpiochip_remove(&bgc->gc);
kfree(bgc);
return err;
}
EXPORT_SYMBOL_GPL(bgpio_remove);
int __devinit bgpio_init(struct bgpio_chip *bgc,
struct device *dev,
unsigned long sz,
void __iomem *dat,
void __iomem *set,
void __iomem *clr,
void __iomem *dirout,
void __iomem *dirin,
bool big_endian)
{
struct device *dev = &pdev->dev;
struct bgpio_pdata *pdata = dev_get_platdata(dev);
struct bgpio_chip *bgc;
int ret;
int ngpio;
bgc = devm_kzalloc(dev, sizeof(*bgc), GFP_KERNEL);
if (!bgc)
return -ENOMEM;
if (!is_power_of_2(sz))
return -EINVAL;
ret = bgpio_setup_io(pdev, bgc);
bgc->bits = sz * 8;
if (bgc->bits > BITS_PER_LONG)
return -EINVAL;
spin_lock_init(&bgc->lock);
bgc->gc.dev = dev;
bgc->gc.label = dev_name(dev);
bgc->gc.base = -1;
bgc->gc.ngpio = bgc->bits;
ret = bgpio_setup_io(bgc, dat, set, clr);
if (ret)
return ret;
ngpio = bgc->bits;
if (pdata) {
bgc->gc.base = pdata->base;
if (pdata->ngpio > 0)
ngpio = pdata->ngpio;
} else {
bgc->gc.base = -1;
}
ret = bgpio_setup_accessors(pdev, bgc);
ret = bgpio_setup_accessors(dev, bgc, big_endian);
if (ret)
return ret;
spin_lock_init(&bgc->lock);
ret = bgpio_setup_direction(pdev, bgc);
ret = bgpio_setup_direction(bgc, dirout, dirin);
if (ret)
return ret;
bgc->data = bgc->read_reg(bgc->reg_dat);
bgc->gc.ngpio = ngpio;
bgc->gc.dev = dev;
bgc->gc.label = dev_name(dev);
return ret;
}
EXPORT_SYMBOL_GPL(bgpio_init);
platform_set_drvdata(pdev, bgc);
#ifdef CONFIG_GPIO_BASIC_MMIO
ret = gpiochip_add(&bgc->gc);
if (ret)
dev_err(dev, "gpiochip_add() failed: %d\n", ret);
static void __iomem *bgpio_map(struct platform_device *pdev,
const char *name,
resource_size_t sane_sz,
int *err)
{
struct device *dev = &pdev->dev;
struct resource *r;
resource_size_t start;
resource_size_t sz;
void __iomem *ret;
*err = 0;
r = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
if (!r)
return NULL;
sz = resource_size(r);
if (sz != sane_sz) {
*err = -EINVAL;
return NULL;
}
start = r->start;
if (!devm_request_mem_region(dev, start, sz, r->name)) {
*err = -EBUSY;
return NULL;
}
ret = devm_ioremap(dev, start, sz);
if (!ret) {
*err = -ENOMEM;
return NULL;
}
return ret;
}
static int __devexit bgpio_remove(struct platform_device *pdev)
static int __devinit bgpio_pdev_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct resource *r;
void __iomem *dat;
void __iomem *set;
void __iomem *clr;
void __iomem *dirout;
void __iomem *dirin;
unsigned long sz;
bool be;
int err;
struct bgpio_chip *bgc;
struct bgpio_pdata *pdata = dev_get_platdata(dev);
r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dat");
if (!r)
return -EINVAL;
sz = resource_size(r);
dat = bgpio_map(pdev, "dat", sz, &err);
if (!dat)
return err ? err : -EINVAL;
set = bgpio_map(pdev, "set", sz, &err);
if (err)
return err;
clr = bgpio_map(pdev, "clr", sz, &err);
if (err)
return err;
dirout = bgpio_map(pdev, "dirout", sz, &err);
if (err)
return err;
dirin = bgpio_map(pdev, "dirin", sz, &err);
if (err)
return err;
be = !strcmp(platform_get_device_id(pdev)->name, "basic-mmio-gpio-be");
bgc = devm_kzalloc(&pdev->dev, sizeof(*bgc), GFP_KERNEL);
if (!bgc)
return -ENOMEM;
err = bgpio_init(bgc, dev, sz, dat, set, clr, dirout, dirin, be);
if (err)
return err;
if (pdata) {
bgc->gc.base = pdata->base;
if (pdata->ngpio > 0)
bgc->gc.ngpio = pdata->ngpio;
}
platform_set_drvdata(pdev, bgc);
return gpiochip_add(&bgc->gc);
}
static int __devexit bgpio_pdev_remove(struct platform_device *pdev)
{
struct bgpio_chip *bgc = platform_get_drvdata(pdev);
return gpiochip_remove(&bgc->gc);
return bgpio_remove(bgc);
}
static const struct platform_device_id bgpio_id_table[] = {
......@@ -506,21 +525,23 @@ static struct platform_driver bgpio_driver = {
.name = "basic-mmio-gpio",
},
.id_table = bgpio_id_table,
.probe = bgpio_probe,
.remove = __devexit_p(bgpio_remove),
.probe = bgpio_pdev_probe,
.remove = __devexit_p(bgpio_pdev_remove),
};
static int __init bgpio_init(void)
static int __init bgpio_platform_init(void)
{
return platform_driver_register(&bgpio_driver);
}
module_init(bgpio_init);
module_init(bgpio_platform_init);
static void __exit bgpio_exit(void)
static void __exit bgpio_platform_exit(void)
{
platform_driver_unregister(&bgpio_driver);
}
module_exit(bgpio_exit);
module_exit(bgpio_platform_exit);
#endif /* CONFIG_GPIO_BASIC_MMIO */
MODULE_DESCRIPTION("Driver for basic memory-mapped GPIO controllers");
MODULE_AUTHOR("Anton Vorontsov <cbouatmailru@gmail.com>");
......
......@@ -13,9 +13,64 @@
#ifndef __BASIC_MMIO_GPIO_H
#define __BASIC_MMIO_GPIO_H
#include <linux/gpio.h>
#include <linux/types.h>
#include <linux/compiler.h>
struct bgpio_pdata {
int base;
int ngpio;
};
struct device;
struct bgpio_chip {
struct gpio_chip gc;
unsigned long (*read_reg)(void __iomem *reg);
void (*write_reg)(void __iomem *reg, unsigned long data);
void __iomem *reg_dat;
void __iomem *reg_set;
void __iomem *reg_clr;
void __iomem *reg_dir;
/* Number of bits (GPIOs): <register width> * 8. */
int bits;
/*
* Some GPIO controllers work with the big-endian bits notation,
* e.g. in a 8-bits register, GPIO7 is the least significant bit.
*/
unsigned long (*pin2mask)(struct bgpio_chip *bgc, unsigned int pin);
/*
* Used to lock bgpio_chip->data. Also, this is needed to keep
* shadowed and real data registers writes together.
*/
spinlock_t lock;
/* Shadowed data register to clear/set bits safely. */
unsigned long data;
/* Shadowed direction registers to clear/set direction safely. */
unsigned long dir;
};
static inline struct bgpio_chip *to_bgpio_chip(struct gpio_chip *gc)
{
return container_of(gc, struct bgpio_chip, gc);
}
int __devexit bgpio_remove(struct bgpio_chip *bgc);
int __devinit bgpio_init(struct bgpio_chip *bgc,
struct device *dev,
unsigned long sz,
void __iomem *dat,
void __iomem *set,
void __iomem *clr,
void __iomem *dirout,
void __iomem *dirin,
bool big_endian);
#endif /* __BASIC_MMIO_GPIO_H */
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